Vibratory conveyors are generally known in the art for transporting objects using a vibratory force. Such conveyors typically include a deck or other structure that has a conveying surface which defines a path along which objects are conveyed. Depending on the application, the path defined by the deck may be straight, curved, inclined, declined, spiral, or other configuration.
The deck is typically constructed of plate steel. As a result, when viewed in cross-section, the conveying surface defined by the deck is typically “flat” across the width of the deck. Stated alternatively, the conveying surface is substantially linear across its width.
While a flat deck is satisfactory for many applications, it may cause unintended and undesirable results when used to convey certain objects. For example, when conveying generally cylindrical objects such as cam shafts along a flat deck, the objects may roll transversely across the width of the deck, and therefore are not located on the deck with any degree of certainty. In addition, the cylindrical objects may become oriented transversely across the deck, and therefore more easily roll into and possibly damage other objects on the deck.
Flat decks are also difficult to employ for certain path configurations. In a spiral conveyor, for example, it is preferable to form the deck in a helicoid shape. To approximate the helicoid shape with flat plate steel, several bends such as cross crimps are typically formed in the deck. Such cross crimps, however, create abrupt changes in the pitch of the deck and cause the conveying surface to be non-linear across its width. Consequently, the cross-crimps create localized high wear area and non-uniform stresses in the deck. These problems are exacerbated during thermal expansion and contraction, which can be significant when the spiral conveyor is used for heating or cooling of the objects being conveyed. In addition, the need for cross crimps or other bends in the deck increases manufacturing costs and makes assembly more difficult, especially for conveyors that are constructed as multiple sub-assemblies that are mated together, such as for large conveyor sizes.